// Node.js 20+. No packages required. Optional key: DATASCOOP_API_KEY.
const endpoint = "https://datascoop.io/v1/datasets/cqc/query";
const dataset = "cqc";
const filters = {
  "careHome": "true",
  "localAuthorityExact": "Devon",
  "serviceType": "Nursing homes"
};
const PAGE_SIZE = 25, MAX_ROWS = 2500, MAX_PAGES = 100;
const headers = { Accept: "application/json" };
const key = (process.env.DATASCOOP_API_KEY || "").trim();
if (key) headers.Authorization = "Bearer " + key;

async function retrieve() {
  const rows = [];
  let total = null, importedAt = null, first = null;
  for (let page = 0; page < MAX_PAGES; page++) {
    const url = new URL(endpoint);
    url.search = new URLSearchParams({ ...filters, strict_filters: "1",
      limit: String(PAGE_SIZE), offset: String(rows.length) });
    const response = await fetch(url, { headers, signal: AbortSignal.timeout(30000) });
    if (!response.ok) throw new Error("Query failed: HTTP " + response.status +
      ". Check filters and access; retry later for rate limits or server errors.");
    const result = await response.json();
    if (result.dataset !== dataset || !Array.isArray(result.rows) ||
        result.rows.some(row => !row || typeof row !== "object" || Array.isArray(row)) ||
        !Array.isArray(result.ignored) || result.ignored.length ||
        !Number.isSafeInteger(result.total) || result.total < 0 ||
        result.offset !== rows.length || result.returned !== result.rows.length ||
        result.returned > PAGE_SIZE || typeof result.truncated !== "boolean") {
      throw new Error("Unexpected query response; no partial result was printed.");
    }
    if (result.total > MAX_ROWS) throw new Error("More than " + MAX_ROWS +
      " rows match. Narrow the filters or review the bound before increasing it.");
    for (const [name, value] of Object.entries(filters)) {
      if (String(result.applied_filters?.[name]) !== String(value))
        throw new Error("A requested filter was not applied: " + name);
    }
    const imported = result.provenance?.imported_at;
    if (typeof imported !== "string" || !Number.isFinite(Date.parse(imported)))
      throw new Error("Import date is missing; no partial result was printed.");
    if (first === null) { first = result; total = result.total; importedAt = imported; }
    if (result.total !== total || imported !== importedAt)
      throw new Error("The import or match count changed. Run the request again.");
    const next = rows.length + result.returned;
    if (next > total || result.truncated !== (next < total) ||
        (result.returned === 0 && next < total))
      throw new Error("Pagination stopped making sense; no partial result was printed.");
    rows.push(...result.rows);
    if (rows.length === total) return { dataset, filters, total, rows,
      provenance: first.provenance, licence: first.licence, attribution: first.attribution };
  }
  throw new Error("Page limit reached. Narrow the filters; no partial result was printed.");
}

try {
  const result = await retrieve();
  if (result.total === 0) console.error("No matching records. Check the selected area and filters.");
  // Keep provenance and attribution with cached or republished data.
  console.log(JSON.stringify(result, null, 2));
} catch (error) {
  console.error(error instanceof Error ? error.message : "Request failed.");
  process.exitCode = 1;
}